Well, I've done a couple of fixed mode, normal difficulty runs to examine how to the stats transfer, and then tried the file out on RD's normal mode. I felt it was a relatively interesting study for those interested in fixed mode, and how useful those particular stats are in RD. Lets get some generalities out of the way first. Laguz and pre-promotes will cap nearly nothing, so its pointless to use them for transfer runs. The bulk of the Greil Merc levels are fairly simple, so there's very little reason to overemphasize them. On the other hand, there's a reason why part one is considered the hardest part of the game.
All right. Why should you do a fixed mode run for transfer? First off, its relaxing. No counting stat gains during levelup, no constant resetting for better stats, and much faster gameplay because after the initial planning there's very few things you have to keep track of. The final upside is you get a surprisingly decent amount of transfers. The downside of fixed mode is your selection of characters is much smaller, like the pre-promote issue I talked about. Below, I'll introduce which characters I think are worthy and what planning you need for them.
As a quick reminder, I will often say, "maybe this stat booster or that blah blah blah." Why is there a maybe? Mostly because of enemy modifiers. Different enemies give different growths, so stats can be skewed. Plus there are weapon/item modifiers you may have forgotten or ignored. So not all runs are identical, but they should be close.
Jill - potentially caps STR SKL SPD DEF
Jill is an ugly one to start with, but she's also the first noteworthy returning character. Why ugly? Because she naturally caps nothing. It is possible to cap STR and SKL naturally depending on what you fight, but due to weapon/enemy modifiers that's not even a guarantee. My suggestion is to equip an Archer/Thief Band as soon as you get her and that will take care of most of the problems.
STR - using Steel Weapons will allow you to usually cap STR. If not, feed an Energy Drop. They're not important, no one else needs them.
SKL - Thief Band should take care of this. If not, Secret Books are fine.
SPD - This is the ugly one. With Thief Band, hopefully you will only need 1 Speedwing to cap. Thankfully you get 3 through the game, so it may come down to using 2.
DEF - I didn't cap this, but I do have a theory. If you equip the Wyvern Band, use a lot of Silver Weapons, and feed all the Dracoshields, you can cap DEF, but you might take a hit on STR SKL and SPD. Of course then you can feed her more boosters. Could be worth it.
Is Jill worth it? Yes. She's a monster. She can probably do away with the STR and SPD and gain them naturally in RD, but the +2 SkL is so good. If you want to transfer, I strongly suggest at least capping SKL so she doesn't miss every other shot.
Zihark - caps STR SKL SPD.
You can't screw this up, especially if you use a lot of Steel weapons. Boring, no analysis needed.
Is Zihark worth it? Mostly yes. Zihark is a great character, and giving him extra stats is cool. The minor downside is the +2 str makes it so he has problems just weakening the enemy early on and he tends to outright kill them in RD, even with Bronze weaponry. Not a problem in the long run.
Marcia - caps STR SKL SPD.
Pretty straightfoward. Caps them naturally, no effort required.
Is Marcia worth it? Yes. 2-Prologue is easy enough, but 2-3 and 2-Endgame is when a boosted Marcia shines. Her availability is poor, so the extra boosts go a long way.
Nephnee - caps STR SKL SPD.
Again, pretty easy. It doesn't look like Nephnee caps STR normally, but a combination of a Fighter Band, Steel weaponry, and fighting non-mage enemies rocket up that STR growth.
Is Nephnee worth it? Bare. She is already a great unit, easily one of your best lance users. 2-1 is really tough on her though, and every bonus you get makes that stage that much easier. After that, her normal growths easily smooth over any bonuses you obtained. Useful, but if you want to transfer a lot of other units or do some obscure run in RD, its not very painful to ditch her in PoR.
Brom - potentially caps HP STR SKL SPD DEF
Brom is my choice for the amazing Knight Ward. With it, he will cap SPD. His STR and SKL caps fairly naturally, no worries there. Maybe an Energy Drop and/or a Secret Book, but you get quite a few of those. Needs a single Angelic Robe for HP.
Is Brom worth it? I say yes. He comes in early in part 2, and stays around till the end. Unlike Gatrie, who is easily overshadowed by the rest of the Greil Mercs, he comes at a time where you have no choice but to use him quite a bit. The bonuses do stand out, especially the SPD.
Largo - potentially caps HP STR SKL SPD.
Caps HP STR SKL naturally. Will always be 2 SPD short of capping. Enter Speedwing.
Is Largo - ahem Calill worth it? Barely. Her availability is worse than Marcia. The +2 SPD is fairly pointless since you can't double anyways, its really easy to be safe in 2-E where it matters the most, and her skill is not entirely lacking. Her endgame potential is mediocre as well. I only mentioned this because Largo caps a lot of stuff and is easy to use.
Ike - potentially caps HP STR SKL SPD DEF RES
Caps STR SKL SPD naturally. is 2 away for DEF, enters Dracoshield, unless you want to use both of them on Jill. HP is possible but not recommended, since you need both Angelic Robes. RES is the fun one. He's about 7 away from capping. Enter the awesomeness of stat augmentation.
RES - first off, equip a Priest Band ASAP. When you have the chance, buy 3-4 Slim Swords - they add RES. You could also kill every mage and priest you come across with Ike, but that's a bit of overkill. After this, its simple. Ike has enough brute force to use Slims and stay useful. The +10% RES gain from Priest Band + Slims will push Ike up 3-4 points of RES, at which point you feed him the 2 Talismans.
Theoretically, it may be possible to cap all those I listed. Level up with a mix of Priest Band and Fighter Band. Use Slims. Intentionally save most mages/priests for Ike. You might just get enough HP and RES to need only 1 robe and 2 talismans.
Is Ike wor-- YES.
Soren - caps MAG SPD SKL RES
Is Soren worth it? I suppose so. At least he caps a lot. Too bad mage caps in RD are a tad low. The only other point I should recommend is to level up Soren using staves. Saves EXP for the others.
Ilyana. You would think she'll be useful, recruited on one of the hardest stages in RD. Sadly, her growths suck. She'll cap RES, and nothing else. You need the Mage Band PLUS Spirit Dusts to cap MAG, and she'll need Secret Books for SKL. And after all that work and carrying around this dead weight, you get only 1 marginally useful stat - SKL. Yes, my Ilyana won't miss every other shot, and misses every fourth shot instead. Whoopee. The only upside is Ilyana has the funniest support convos every. What a sad joke.
Sothe. Hey, I don't have to cap stuff, and I profit! What's the problem? Well, Sothe kind of sucks. Hard to level up, sucks up EXP because of Blossom, blah blah blah. The kicker is his lvl1 stats in RD are spectacular compared to PoR. You're hard-pressed to get anything out of it, even harder to get anything useful. Plus his caps are fairly low in RD anyways, so it doesn't help with the issue of BEXP. If you do feed him every stat booster in the game, sure, he'll turn out decent, but then, YOU JUST FED HIM EVERY BOOSTER IN THE GAME.
The Paladins. They got slightly shafted in RD. I suppose everyone realized how ridiculously godlike an all paladin team is in PoR. Geoffrey's team handles their mission just fine, and Ike's team, well, they're overpowered enough already. A boosted Marcia already helps Geoffrey's team quite a bit, esp. in the stage Marauders (forgot number).
Final thoughts? I found Fixed Mode enough for transfers. I had a fun time doing it, and I would imagine constantly resetting for better levelups will suck all that fun out. Thanks for reading.